The invention is directed to a process for the production of aromatic or heteroaromatic substituted acetonitriles by the reaction of methyl substituted aromatics or heteroaromatics with cyanogen chloride in the gas phase at elevated temperature. The aromatic or heteroaromatic substituted acetonitriles among other uses are employed as starting materials for the production of medicines and plant protective agents.
It is known to produce aromatic substituted acetonitrile by reaction of methyl substituted aromatics with cyanogen chloride in the gas phase in a reaction tube at a temperature of 500.degree. to 775.degree. C. The starting materials for this are fed in as liquids and vaporized at the entrance of the reactor tube (Grimm, Ind. Eng. Chem., Prod. Res. Div. Vol. 14 (1975) pages 158 to 161. To be sure a favorable transformation is produced in this process but the yield of pure substituted acetonitriles is only moderate. The space-time-yield also is moderate. Besides, decomposition products, particularly carbon black, deposit in the reaction tube, so that the tube after a relatively short operating time is clogged. The process consequently is unusable for use on an industrial scale.